/**
 * Copyright (C) 2002-2015   The FreeCol Team
 * <p>
 * This file is part of FreeCol.
 * <p>
 * FreeCol is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 * <p>
 * FreeCol is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * <p>
 * You should have received a copy of the GNU General Public License
 * along with FreeCol.  If not, see <http://www.gnu.org/licenses/>.
 */

package net.sf.freecol.server.ai;

import java.util.Comparator;


/**
 * A special comparator to sort the production cache with.
 */
public class CacheEntryComparator implements Comparator< ProductionCache.Entry >
{

    public int compareProduction( ProductionCache.Entry entry1, ProductionCache.Entry entry2 )
    {
        return entry2.getProduction( ) - entry1.getProduction( );
    }

    @Override
    public int compare( ProductionCache.Entry entry1, ProductionCache.Entry entry2 )
    {

        int production = compareProduction( entry1, entry2 );
        if ( production != 0 )
        {
            return production;
        }
        else if ( entry1.isExpert( ) )
        {
            if ( entry2.isExpert( ) )
            {
                return 0;
            }
            else
            {
                return - 1;
            }
        }
        else if ( entry2.isExpert( ) )
        {
            return 1;
        }
        else if ( entry1.unitUpgradesToExpert( ) )
        {
            if ( entry2.unitUpgradesToExpert( ) )
            {
                // both can be upgraded to expert: compare experience
                return entry2.getUnit( ).getExperience( )
                        - entry1.getUnit( ).getExperience( );
            }
            else
            {
                return - 1;
            }
        }
        else if ( entry2.unitUpgradesToExpert( ) )
        {
            return 1;
        }
        else if ( entry1.unitUpgrades( ) )
        {
            if ( entry2.unitUpgrades( ) )
            {
                // both can be upgraded: compare wasted experience
                return entry1.getUnit( ).getExperience( )
                        - entry2.getUnit( ).getExperience( );
            }
            else
            {
                return - 1;
            }
        }
        else if ( entry2.unitUpgrades( ) )
        {
            return 1;
        }
        else if ( entry1.isOtherExpert( ) )
        {
            if ( entry2.isOtherExpert( ) )
            {
                return 0;
            }
            else
            {
                // prefer non-experts
                return 1;
            }
        }
        else if ( entry2.isOtherExpert( ) )
        {
            return - 1;
        }
        else
        {
            return 0;
        }
    }
}

